Information
-
Patent Grant
-
6511295
-
Patent Number
6,511,295
-
Date Filed
Tuesday, November 20, 200123 years ago
-
Date Issued
Tuesday, January 28, 200322 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
-
CPC
-
US Classifications
Field of Search
US
- 417 441
- 417 4101
- 417 4105
- 417 902
- 062 2592
-
International Classifications
-
Abstract
Compressors may include a compressor housing having a compression chamber defined within the compressor housing. The compression chamber is preferably arranged and constructed to compress and discharge a fluid drawn into the compression chamber. A unit housing may be coupled to the compressor housing. A control device may be disposed within the unit housing and the control device preferably controls electric components of the compressor. Further, a suction passage is preferably defined to introduce the fluid into the compression chamber. The suction passage preferably penetrates through the unit housing so as to directly cool the control device due to the fluid flowing through the suction passage.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to compressors and more particularly, to compressors that include electrical driven devices, such as an electric motor for driving the compressor.
2. Description of the Related Art
A known compressor is disclosed in Japanese Laid-Open Patent Publication No. 2000-255252 and includes an electric motor and an inverter. The inverter controls the electric motor in order to drive the compressor. Further, the inverter is cooled by refrigerant gas drawn into the compressor. More specifically, the inverter includes a heat radiator that contacts a suction passage for drawing the refrigerant into the compressor and the heat radiator cools the inverter.
SUMMARY OF THE INVENTION
It is one object of the present teachings to provide improved compressors that can more effectively cool an electrical control device of the compressor.
In one embodiment of the present teachings, representative compressors may include, for example, a compressor housing, a compression chamber, a unit housing, a control device and a suction passage. The compression chamber may be defined within the compressor housing and fluid drawn into the compression chamber is compressed and then discharged. The control device may be disposed within the unit housing and the control device preferably controls electric devices within the compressor. For example, an electric motor may be disposed within the compressor housing and may drive the compressor. Further, an inverter is one representative example of a control device according to the present teachings.
The suction passage may introduce fluid, such as a refrigerant gas, into the compression chamber. The temperature of fluid within the suction passage is typically relatively low compared to the temperature of the fluid that has been compressed by and discharged from the compressor. Preferably, the suction passage penetrates into the unit housing such that the fluid within the suction passage may directly cool the control device (e.g., an inverter) disposed within the unit housing.
If the suction passage penetrates into the unit housing, the control device within the unit housing can be directly and effectively cooled. Although the fluid in the suction passage can directly cool the control device, the control device is prevented from being directly exposed to the fluid due to separation provided by the suction passage. Therefore, the control device can be prevented from corroding, which may cause the control device to malfunction.
Only objects, features and advantage of the present invention will be readily understood after reading the following detailed description together with the accompanying drawings and the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1
shows a representative scroll compressor.
FIG. 2
shows a cross sectional view taken along line II—II in FIG.
1
.
FIG. 3
shows a representative disposition for the respective switching elements.
FIG. 4
shows a cross sectional view of a modification of the representative embodiment.
FIG. 5
shows a modification of the arrangement of the switching elements.
FIG. 6
shows another modification of the arrangement of the switching elements.
FIG. 7
shows a further modification of the arrangement of the switching elements.
DETAILED DESCRIPTION OF THE INVENTION
Representative compressors are taught that may preferably include a compressor housing. A compression chamber may be defined within the compressor housing. A unit housing may be disposed proximally to the compressor housing and a control device may be disposed within the unit housing. The control device preferably functions to control the electric components of the compressor. A suction passage preferably penetrates through the unit housing so as to provide an effective surface for directly cooling the control device.
In one embodiment of the present teachings, an adiabatic zone may preferably be provided between the compressor housing and the unit housing. In another embodiment of the present teachings, the unit housing may preferably be disposed on or adjacent to the outer surface of the compressor housing. Preferably, an electric motor drives the compressor in accordance with signals communicated by the control device, which may be, e.g., an inverter. In another embodiment of the present teachings, the position of the adiabatic zone may be chosen in accordance with the disposition of the electric components of the compressor.
In further embodiment of the present teachings, the adiabatic zone may be defined by an air-layer provided between the compressor housing and the unit housing. Optionally, the adiabatic zone may comprise a heat sink material. In another embodiment, a heat insulating material may be disposed within the unit housing.
In another aspect of the present teachings, heat-generating elements of the control device may preferably be disposed within the unit housing in a position that is close to and outer surface of the suction passage. For example, heat-generating device(s) may be disposed so as to contact directly the outer surface of the suction passage or a clearance may separate the heat-generating device(s) from the outer surface of the suction passage.
In another aspect of the present teachings, the outer surface of the suction passage may substantially conform to the outer shape of the heat-generating elements. For example, the outer surface of the suction passage may include a planar surface. Moreover, the suction passage may preferably include a plurality of mounting surfaces disposed in the circumferential direction of the suction passage. Thus, the heat-generating elements may be disposed on the respective mounting surfaces.
Each of the additional features and method steps disclosed above and below may be utilized separately or in conjunction with other features and method steps to provide improved compressors and methods for designing and using such compressors. Representative examples of the present invention, which examples utilize many of these additional features and method steps in conjunction, will now be described in detail with reference to the drawings. This detailed description is merely intended to teach a person of skill in the art further details for practicing preferred aspects of the present teachings and is not intended to limit the scope of the invention. Only the claims define the scope of the claimed invention. Therefore, combinations of features and steps disclosed in the following detail description may not be necessary to practice the invention in the broadest sense, and are instead taught merely to particularly describe some representative examples of the invention, which detailed description will now be given with reference to the accompanying drawings. Further, the features disposed in the specification and dependent claims may be combined in ways that are not specifically enumerate in order to provide additional useful embodiments of the present teachings.
A representative compressor is shown in
FIGS. 1
to
3
and may preferably be utilized within a refrigerant circulation circuit in a vehicle air conditioning system. As shown in
FIG. 1
, a representative compressor
1
may include a compressor housing
7
, a compression chamber
32
defined between a stationary scroll
2
and a movable scroll
20
within the compressor housing
7
. An electric motor
45
may be provided within the compressor housing
7
in order to drive the movable scroll
20
. An inverter
60
may be within a unit housing
70
and a suction passage
63
may penetrate through the unit housing
70
in order to directly cool the inverter
60
. As discussed above, an inverter is one representative example of a “control device” or a “means for controlling” according to the present teachings.
The compressor housing
7
may include a center housing
4
, a motor housing
6
and an end housing
2
a
. A stationary scroll
2
is provided within the end housing
2
a
. A movable scroll
20
and other appropriate devices for driving the movable scroll
20
are disposed within the compressor housing
7
. A first end surface of the center housing
4
is coupled to the end housing
2
a
and a second end surface of the center housing
4
is coupled to the motor housing
6
. A drive shaft
8
is rotatably supported by radial bearings
10
and
12
respectively disposed within the center housing
4
and the motor housing
6
. Within the center housing
4
, a crankshaft
14
is integrally coupled to the end of the drive shaft
8
. Although the drive shaft
8
is driven by an electric motor
45
disposed in the motor housing
6
in this representative embodiment, the present teachings are also, e.g., naturally applicable to other types of scroll compressors, as well as compressors in general, in which the drive shaft
8
is mechanically driven by the vehicle engine via belts.
Two mutually parallel planar portions
14
a
are defined on the crankshaft
14
. In
FIG. 1
, however, only one planar portion
14
a
is shown for the sake of convenience of explanation. A bush
16
is disposed around the planar surfaces
14
a
so that the bush
16
may rotate together with the crankshaft
14
. A balancing weight
18
is attached to one end of the bush
16
so that the balancing weight
18
can rotate together with the crankshaft
14
. The movable scroll
20
includes a tubular boss
24
a
on the surface opposite to the stationary scroll
2
(on the right side of the movable scroll
20
in FIG.
1
). Further, the bush
16
is connected to the inner circumferential surface of the boss
24
a
by means of a needle bearing
22
. The needle bearing
22
is coupled to the inner circumferential surface of the boss
24
a
by means of a stopper ring (not particularly shown in the drawings).
The stationary scroll
2
includes a stationary volute wall
28
that protrudes from a base plate
26
of the stationary scroll
2
towards the movable scroll
20
. The movable scroll
20
includes a movable volute wall
30
that protrudes from the base plate
24
of the movable scroll
20
towards the stationary scroll
2
. The stationary volute wall
28
and the movable volute wall
30
are disposed adjacent to each other and preferably are aligned to engage or mesh with each other. The volute walls are also known in the art as spiral wraps and naturally, these terms can be utilized interchangeably.
The stationary volute wall
28
and the movable volute wall
30
make contact with each other at a plurality of positions and are positioned in meshing engagement. As the result, a plurality of compression chambers
32
having a crescent shape is defined within a space surrounded by the stationary scroll base plate
26
, the stationary volute wall
28
, the movable scroll base plate
24
and the movable volute wall
30
. When the drive shaft
8
rotates, the crankshaft
14
revolves or orbits around the rotational axis of the drive shaft
8
. The rotational axis may be defined as the center, longitudinal axis of the drive shaft
8
. Thus, the distance between the crankshaft
14
and the rotational axis of the drive shaft
8
defines the diameter of the orbital path. When the movable scroll
20
revolves or orbits about the rotational axis of the drive shaft
8
, the balancing weight
18
offsets the centrifugal force caused by the revolution of the movable scroll
20
. The crank shaft
14
that rotates together with the drive shaft
8
, the bush
16
, the needle bearing
22
provided between the crank shaft
14
and the boss
24
a
of the movable scroll
20
define a revolutionary (orbital) mechanism
19
to transmit the rotational torque of the drive shaft
8
to the movable scroll
20
as a revolutionary (orbital) movement.
A discharge port
50
is defined within the base plate
26
of the stationary scroll
2
. Further, a discharge valve
54
is provided within a discharge chamber
52
. The discharge valve
54
is disposed to face the discharge port
50
in order to open and close the discharge port
50
. The discharge valve
54
includes a reed valve
56
and a retainer
58
. The reed valve
56
has a shape that is sufficient to cover the opening of the discharge port
50
. The retainer
58
faces the reed valve
56
and is disposed on the opposite side of the discharge port
50
. Within the discharge chamber
52
, the reed valve
56
and the retainer
58
are fixed to the inner surface of the base plate
26
of the stationary scroll
2
by means of a bolt
54
a.
The reed valve
56
is opened and closed based upon the pressure difference between the pressure within the discharge port
50
or the compression chamber
32
and the pressure within the discharge chamber
52
. The retainer
58
supports the reed valve
56
and also defines the maximum aperture of the reed valve
56
.
A plurality of spaces (recesses)
34
are provided at equal angles within the center housing
4
to face base plate
24
of the movable scroll
20
. First auto-rotation preventing pins
36
and second auto rotation preventing pins
38
are disposed within respective spaces
34
. The first auto-rotation preventing pins
36
are fixed to the center housing
4
and penetrate from the center housing
4
toward the movable scroll
20
. The second auto-rotation preventing pins
38
are fixed to the movable scroll
20
and protrude from the base plate
24
of the movable scroll
20
to the center housing
4
within the space
34
. In this embodiment, a total of four first auto-rotation preventing pins
36
and second auto-rotation preventing pins
38
are provided. However, only one of each of the first and second auto-rotation preventing pins
36
,
38
are shown in FIG.
1
. Auto-rotation of the movable scroll
20
can be prevented by the engagement of the first auto-rotation preventing pins
36
with the second auto-rotation preventing pins
38
.
With respect to the electric motor
45
, a stator
46
is provided on the inner circumferential surface of the motor housing
6
. Further, a rotor
48
is coupled to the drive shaft
8
. The stator
46
and the rotor
48
define an electric motor that rotates the drive shaft
8
. Thus, the present scroll compressors are particularly useful for hybrid or electric cars that operate using electric power. However, an electric motor is not essential to the present teachings and the present scroll compressor can be modified for use with internal combustion engines.
In the representative compressor
1
as described above, the compressor housing
7
has a flat-shaped attachment surface
7
a
defined on the outer upper surface of the compressor housing
7
. Preferably, the unit housing
70
is coupled to the attachment surface
7
a
. As shown in
FIG. 1
, an attachment plate
65
supports a plurality of condensers (capacitors)
64
. The inverter
60
may be disposed within the unit housing
70
and preferably includes two elements. The first element may be a relatively high heat-generating element, such as switching element
62
, which generate a relatively large amount of heat. The second element may be a relatively low heat-generating element, such as condenser
64
, which generates a relatively small amount of heat.
The switching elements
62
are preferably disposed within a cylindrical portion
70
a
of the unit housing
70
. As shown in
FIG. 1
, the suction passage
63
preferably penetrates through the unit housing
70
and may include a cylindrical member
63
a
and a refrigerant introducing passage
63
b
. The refrigerant introducing passage
63
b
is defined inside the cylindrical member
63
a
. The switching elements
62
preferably directly contact the outer surface of the refrigerant introducing passage
63
b
of the suction passage
63
.
FIG. 3
shows a cross-sectional view of the suction passage
63
, in which a plurality of flat-shaped attachment surfaces
63
c
are disposed around the outer periphery of the cylindrical member
63
a
in order to couple the respective switching elements
62
onto the attachment surfaces
63
c
. In this representative embodiment, three attachment surfaces
63
c
are formed so as to form a triangular shape.
As shown in
FIG. 1
, a first end of the suction passage
63
communicates with the suction port
44
of the compressor chamber
32
. A second end of the suction passage
63
communicates with the refrigerant-returning line (omitted from the drawings) of the external air conditioning circuit.
The unit housing
70
preferably comprises a heat insulating material, such as a synthetic resin. A connecting member
70
c
may be utilized to attach the bottom plate
70
b
to the attachment surface
7
a
of the compressor housing
7
. A clearance C may be defined between the unit housing
70
and the compressor housing. Further, clearance C is one representative example of an “adiabatic zone defined by an air layer” according to the present teachings.
The switching elements
62
in the unit housing
70
and the electric motor
45
within the motor housing
6
are electrically connected by a conducting pin
66
and a conducting wires
67
and
68
. The conducting pin
66
extends through the unit housing
70
and the compressor housing
7
. Electric power to drive the electric motor
45
is supplied from the switching elements
62
via the conducting pin
66
and the conducting wires
67
,
68
.
The drive shaft
8
is rotated by means of the electric motor
45
. The electric motor
45
is operated by the inverter
60
disposed within the unit housing
70
. When the crank shaft
14
orbits, the movable scroll
20
, which is connected to the crank shaft
14
by the boss
24
a
and the needle bearing
22
, orbits around the rotational axis of the drive shaft
8
. When the movable scroll
20
orbits with respect to the stationary scroll
2
, refrigerant gas (fluid) is drawn from the suction passage
63
into the compression chamber
32
via a suction port
44
. The compression chamber
32
reduces the volume of the refrigerant gas as the compression chamber moves toward the center of the scrolls
2
,
20
. Due to the volume reduction of the compression chamber
32
and thus the refrigerant gas, the refrigerant gas is compressed and reaches a high-pressure state. The compressed high-pressure refrigerant gas is discharged from the discharge port
50
to the cooling or heating circuit of the vehicle air-conditioning system (not particularly shown in the drawings) via the discharge chamber
52
when the discharge valve
54
opens the discharge port
50
.
The compressed high-pressure refrigerant gas is discharged from the discharge port
50
to the air conditioning system outside of the compressor
1
via a discharge chamber
52
when the discharge valve
54
opens the discharge port
50
. Although it is not particularly shown in the drawings, the high-pressure refrigerant discharged from the representative compressor
1
may be supplied to an air conditioning system that includes a condenser, expansion valve and an evaporator. Then, the refrigerant will be again drawn into the compressor
1
via the suction passage
63
and the suction port
44
. The refrigerant, which has a relatively low-pressure and low-temperature within the suction passage
63
, will then absorb the heat generated by the switching elements
62
within the unit housing
70
. Thus, the heat generating elements, such as switching elements
62
, can be directly and quickly cooled by means of the refrigerant gas flowing through the suction passage
63
. Naturally, because the refrigerant gas passing through the suction passage
63
directly cool the heat generating elements in the unit housing
70
, no special heat-dissipating equipment, such as a heat radiator, is required to cool the heat generating elements.
According to this representative embodiment, the suction passage
63
directly contacts only the high heat-generating elements, such as the switching elements
62
, disposed within the unit housing
70
. In other words, by functionally separating the inverter
60
into two portions, i.e., high and low heat-generating elements, and by selectively cooling only the high heat-generating elements, the cooling efficiency of the inverter can be maximized. Moreover, as particularly shown in
FIG. 3
, the suction passage
63
includes a plurality of the planar surfaces
63
c
and the flat-shaped switching elements
62
can be coupled to the flat attachment surfaces
63
c
. Therefore, the effective area for cooling the switching elements
62
by the refrigerant gas can be effectively increased.
During the operation of the compressor
1
, the temperature of the compressor housing
7
tends to rise due to the heat generated by the compression of refrigerant gas and due to the heat generated by the electric motor
45
. However, due to the adiabatic zone defined by the clearance C between the unit housing
70
and the compressor housing
7
, the unit housing
70
can be thermally insulated from the compressor housing
7
. Therefore, the inverter
60
within the unit housing
70
can be prevented from being heated by the compressor housing
7
. Further, because the unit housing
70
is formed using a heat insulating material (e.g., a synthetic resin), the unit housing
70
can effectively shield the inverter
60
from the heat radiated by the compressor housing
7
.
On the other hand, when the operation of the compressor
1
is stopped, the refrigerant gas is not compressed and circulated. Therefore, the inverter
60
can not be cooled by the refrigerant gas flowing through the suction passage
63
when the compressor
1
is not operated. However, in such case, due to the adiabatic zone C and the unit housing
70
formed from an insulating material, the temperature of inverter
60
within the unit housing
70
can be prevented from rising due to the heat radiated by the compressor housing
7
.
Because the temperature of the compressor housing
7
will sharply rise when an electric motor
45
is utilized to drive the compressor
1
, the adiabatic zone C may preferably be provided between the compressor housing
7
and the unit housing
70
so as to separate the unit housing
70
from the compressor housing
7
. In this connection, the unit housing
70
is separated from the compressor housing
7
by a minute or small clearance and this clearance defines the adiabatic zone C. According to this representative embodiment, because the unit housing
70
is separated from the compressor housing
7
only by the adiabatic zone C, the length of the electric circuit that is required to connect the electric motor
45
with the inverter
60
can be minimized. Furthermore, the length of the suction passage
63
for cooling the inverter
60
can be also minimized. Thus, the refrigerant gas within the air conditioning circuit can be prevented from receiving relatively high resistance caused by friction between the flowing refrigerant gas and the inside wall of the circuit pipe.
A second representative embodiment is shown in FIG.
4
. The second representative embodiment relates to a modification of the disposition of the suction passage with respect to the unit housing. As shown in
FIG. 4
, in the second representative embodiment, the suction passage
81
is horizontally provided within the unit housing
70
. That is, the suction passage
81
is disposed substantially in parallel with the surface of the compressor housing
7
. The suction passage
81
directly contacts the inverter
60
(electric elements) within the unit housing
70
and the tip of the suction passage
81
communicates with the suction port
44
. The bottom plate
70
b
of the unit housing
70
is coupled to the compressor housing
7
by means of an attaching member
70
c
. An adiabatic zone C is defined between the unit housing
70
and the compressor housing
7
. In other words, the unit housing
70
is separated from the compressor housing
7
by a clearance C. Further, in the second representative embodiment, a heat-sink material
82
is preferably provided on the outer surface of the suction passage
81
and absorbs heat radiated from the compressor housing
7
in order to prevent the temperature of the inverter
60
from excessively rising.
Various modifications of the representative embodiment with respect to the suction passage are shown in
FIGS. 5
to
7
. According to the modification as shown in
FIG. 5
, the cylindrical member
63
may have a square cross section and four attachment surfaces
63
a
. According to the modification as shown in
FIG. 6
, the cylindrical member
63
may have a hexagonal cross section and six attachment surfaces
63
a
. According to the modification as shown in
FIG. 7
, a plate-shaped heat-radiating member
84
may be provided between the cylindrical member
63
and the switching element
62
. The heat radiation member
84
will permit heat to efficiently transfer between the switching element
62
and the cylindrical member
63
.
Naturally, further modifications can be made with respect to the above-described representative embodiments. For example, in the adiabatic zone between the unit housing
70
and housing
7
, a heat insulating material can be utilized instead of the air-layer defined by the clearance C between the unit housing
70
and the compressor housing
7
. Further, the adiabatic zone can be defined by a combination of a heat sink material and a heat insulating material. Moreover, the attachment surfaces
63
a
of the suction passage for attaching the switching element
62
are not limited to flat-shaped surfaces. That is, the switching element
62
and the cylindrical unit
63
may have any mating surface. Further, this invention is applicable to compressors other than the scroll type compressor that was described above.
Further additional teachings that are relevant to the present teachings can be found in U.S. patent application Ser. No. 09/804,219, which teachings are incorporated by reference herein in their entirety.
Claims
- 1. A compressor comprising:a compressor housing having a compression chamber defined within the compressor housing, wherein the compression chamber is arranged and constructed to compress and discharge a fluid drawn into the compression chamber, a unit housing coupled to the compressor housing, a control device disposed within the unit housing, wherein the control device controls electric components of the compressor and a suction passage defined to introduce the fluid into the compression chamber, wherein the suction passage penetrates through the unit housing so as to directly cool the control device due to the fluid flowing through the suction passage.
- 2. A compressor according to claim 1 further comprising an adiabatic zone that is defined between the compressor housing and the unit housing.
- 3. A compressor according to claim 2, wherein the unit housing is disposed on or adjacent to the outer surface of the compressor housing via the adiabatic zone, the control device operates the electric components that are disposed within the compressor housing.
- 4. A compressor according to claim 2, wherein the adiabatic zone is defined between an outer surface of the compressor housing and the unit housing.
- 5. A compressor according to claim 1, wherein the electric components include an electric motor disposed within the compressor housing and causing the compression chamber to compress and discharge the fluid.
- 6. A compressor according to claim 5, wherein the adiabatic zone is disposed proximally to the electric motor.
- 7. A compressor according to claim 5, wherein the adiabatic zone is defined by an air-layer provided between the compressor housing and the unit housing.
- 8. A compressor according to claim 5, wherein the adiabatic zone comprises a heat sink material.
- 9. A compressor according to claim 1, further comprising a heat insulating material disposed within the unit housing.
- 10. A compressor according to claim 1, wherein the control device includes relatively high heat-generating elements that are disposed on an outer surface of the suction passage.
- 11. A compressor according to claim 10, wherein the outer surface of the suction passage conforms to an outer shape of the heat-generating elements.
- 12. A compressor according to claim 10, wherein the outer surface of the suction passage includes a planar surface.
- 13. A compressor according to claim 10, wherein a plurality of mounting surfaces are disposed in the circumferential direction of the suction passage and the heat-generating elements are disposed on the respective mounting surfaces.
- 14. A compressor according to claim 10, wherein a heat radiator is disposed between the suction passage and the heat-generating elements.
- 15. A compressor according to claim 1, wherein the control device comprises relatively high heat generating switching elements, wherein the switching elements are directly mounted on the suction passage.
- 16. A compressor according to claim 15, wherein the control device further comprises a plurality of condensers that are spaced from the suction passage.
- 17. A compressor according to claim 16, further comprising an adiabatic zone defined between an outer surface of the compressor housing and the unit housing, an electric motor disposed within the compressor housing and causing the compression chamber to compress and discharge the fluid and a heat insulating material disposed within the unit housing so as to shield the control device from heat radiated by the compressor housing.
- 18. A compressor comprising:a compressor housing, a compression chamber defined within the compressor housing, the compression chamber compressing and discharging fluid drawn into the compression chamber, a unit housing coupled to the compressor housing, a control device disposed within the unit housing, wherein the control device controls electric components of the compressor and means for directly cooling the control device within the unit housing, wherein the cooling means defines a portion of an air conditioning system that penetrates through the unit housing.
- 19. A compressor according to claim 18, wherein the control device comprises relatively high heat generating switching elements, wherein the switching elements are directly mounted on the cooling means, and a plurality of condensers that are spaced from the cooling means and further comprising an adiabatic zone defined between an outer surface of the compressor housing and the unit housing, an electric motor disposed within the compressor housing and causing the compression chamber to compress and discharge the fluid and a heat insulating material disposed within the unit housing so as to shield the control device from heat radiated by the compressor housing.
- 20. A method comprising passing the fluid through the suction passage disposed within the compressor of claim 1 in order to directly cool the control device disposed within the unit housing.
Priority Claims (1)
Number |
Date |
Country |
Kind |
2000-357967 |
Nov 2000 |
JP |
|
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Number |
Name |
Date |
Kind |
3903710 |
Quatman |
Sep 1975 |
A |
5220809 |
Voss |
Jun 1993 |
A |
6041609 |
Hornsleth et al. |
Mar 2000 |
A |
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Number |
Date |
Country |
62-12471 |
Jan 1987 |
JP |
62-19535 |
Feb 1987 |
JP |
4-80554 |
Mar 1992 |
JP |
2000-255252 |
Sep 2000 |
JP |